﻿using System.Collections;
using System.Windows.Forms;

namespace Cataloger
{
    /// <summary>
    /// This class is an implementation of the 'IComparer' interface.
    /// </summary>
    public class ListViewColumnSorterNosniki : IComparer
    {
		#region Fields (3) 

        /// <summary>
        /// Specifies the column to be sorted
        /// </summary>
        private int ColumnToSort;
        /// <summary>
        /// Case insensitive comparer object
        /// </summary>
        private CaseInsensitiveComparer ObjectCompare;
        /// <summary>
        /// Specifies the order in which to sort (i.e. 'Ascending').
        /// </summary>
        private SortOrder OrderOfSort;

		#endregion Fields 

		#region Constructors (1) 

        /// <summary>
        /// Class constructor.  Initializes various elements
        /// </summary>
        public ListViewColumnSorterNosniki()
        {
            // Initialize the column to '0'
            ColumnToSort = 0;

            // Initialize the sort order to 'none'
            OrderOfSort = SortOrder.None;

            // Initialize the CaseInsensitiveComparer object
            ObjectCompare = new CaseInsensitiveComparer();
        }

		#endregion Constructors 

		#region Properties (2) 

        /// <summary>
        /// Gets or sets the order of sorting to apply (for example, 'Ascending' or 'Descending').
        /// </summary>
        public SortOrder Order
        {
            set
            {
                OrderOfSort = value;
            }
            get
            {
                return OrderOfSort;
            }
        }

        /// <summary>
        /// Gets or sets the number of the column to which to apply the sorting operation (Defaults to '0').
        /// </summary>
        public int SortColumn
        {
            set
            {
                ColumnToSort = value;
            }
            get
            {
                return ColumnToSort;
            }
        }

		#endregion Properties 

		#region Methods (1) 

		// Public Methods (1) 

        /// <summary>
        /// This method is inherited from the IComparer interface.  It compares the two objects passed using a case insensitive comparison.
        /// </summary>
        /// <param name="x">First object to be compared</param>
        /// <param name="y">Second object to be compared</param>
        /// <returns>The result of the comparison. "0" if equal, negative if 'x' is less than 'y' and positive if 'x' is greater than 'y'</returns>
        public int Compare(object x, object y)
        {
            int compareResult;
            ListViewItem listviewX, listviewY;

            // Cast the objects to be compared to ListViewItem objects
            listviewX = (ListViewItem)x;
            listviewY = (ListViewItem)y;
            if (SortColumn == 4)
            {
                long l1 = listviewX.SubItems[ColumnToSort].Text.ZamienNaBajty();
                long l2 = listviewY.SubItems[ColumnToSort].Text.ZamienNaBajty();
                if (OrderOfSort == SortOrder.Ascending)
                {
                    if (l1 > l2)
                        return 1;
                    else if (l1 < l2)
                        return -1;
                    else
                        return 0;
                }
                else if (OrderOfSort == SortOrder.Descending)
                {
                    if (l1 > l2)
                        return -1;
                    else if (l1 < l2)
                        return 1;
                    else
                        return 0;
                }
                else
                {
                    // Return '0' to indicate they are equal
                    return 0;
                }
            }
            if (SortColumn == 6||SortColumn==7)
            {
                long l1 = 0;
                long.TryParse(listviewX.SubItems[ColumnToSort].Text,out l1);
                long l2 = 0;
                long.TryParse(listviewY.SubItems[ColumnToSort].Text,out l2);
                if (OrderOfSort == SortOrder.Ascending)
                {
                    if (l1 > l2)
                        return 1;
                    else if (l1 < l2)
                        return -1;
                    else
                        return 0;
                }
                else if (OrderOfSort == SortOrder.Descending)
                {
                    if (l1 > l2)
                        return -1;
                    else if (l1 < l2)
                        return 1;
                    else
                        return 0;
                }
                else
                {
                    // Return '0' to indicate they are equal
                    return 0;
                }
            }

            // Compare the two items
            compareResult = ObjectCompare.Compare(listviewX.SubItems[ColumnToSort].Text, listviewY.SubItems[ColumnToSort].Text);

            // Calculate correct return value based on object comparison
            if (OrderOfSort == SortOrder.Ascending)
            {
                // Ascending sort is selected, return normal result of compare operation
                return compareResult;
            }
            else if (OrderOfSort == SortOrder.Descending)
            {
                // Descending sort is selected, return negative result of compare operation
                return (-compareResult);
            }
            else
            {
                // Return '0' to indicate they are equal
                return 0;
            }

        }

		#endregion Methods 
    }
}